Glossary

A comprehensive definitions’ list to help you get more background on some of the technical works used in visual art practice

ACID FREE

Acid-free paper is paper that if infused in water yields a neutral or basic pH (7 or slightly greater). It can be made from any cellulose fibber as long as the active acid pulp is eliminated during processing. It is also lignin and sulphur free. Acid-free paper addresses the problem of preserving documents and artwork for long periods.

ACRYLIC

Acrylic resins are a group of related thermoplastic or thermosetting plastic substances derived from acrylic acid, methacrylic acid or other related compounds. Polymethyl acrylate is an acrylic resin used in an emulsified form for lacquer, textile finishes, and adhesives and mixed with clay, to gloss paper. Another acrylic resin is polymethyl methacrylate, which is used to make hard plastics with various light transmitting properties.

ACRYLIC PAINT

Acrylic paint is fast-drying paint containing pigment suspension in acrylic polymer emulsion. Acrylic paints can be diluted with water, but become water-resistant when dry. Depending on how much the paint is diluted (with water) or modified with acrylic gels, media, or pastes, the finished acrylic painting can resemble a watercolour or an oil painting, or have its own unique characteristics not attainable with other media.

ALUMINIUM LEAF

Aluminium leaf or “imitation silver leaf” is pure aluminium and is around 0.6 to 2.0 micrometres thick. It is virtually the same material that the BBC used on Coles ribbons, with the exception that they also hand beat the leaf even thinner. They did this by sandwiching the ribbon between toilet paper and beating with a ball-peen hammer. This “cold forges” the leaf. The aluminium leaf was then annealed for an hour in an oven to restore flexibility.

AGFA PAPER (trademark)

AgfaPhoto GmbH is a European photographic company, formed in 2004 when Agfa-Gevaert sold their Consumer Imaging division. Agfa (the former parent company, merged with film manufacturer Gevaert in 1964) had for many years been well known as a producer of consumer-oriented photographic products including films, photographic papers and cameras. However, within a year of the sell-off, AgfaPhoto had filed for bankruptcy. The various product brands are now being licenced to various companies by the holding firm AgfaPhoto Holding GmbH. Minilab service and chemicals are e.g. now sold by A&O Imaging Solutions, and AgfaPhoto Vista Brand Film is sold by Lupus Imaging & Media.

ARCHES 88

A surface specific for print making, a 100% cotton mould made paper, acid free and buffered. It has an extremely smooth surface with four deckle edges and a registered watermark. As the paper is not size it is very absorbent and therefore recommended for silkscreen printing and if slightly moistened, for intaglio etching.

ARCHES PAPERS

Since 1492, Arches has stood for professional quality for artists. It’s pure cotton products; mould-made in the traditional way, have a natural grain, which resembles that of hand-made paper. This process also produces a more stable paper, whose form is not significantly altered when wet, because of the excellent distribution of its long cotton fibres. Arches Watercolour papers also boast unique sizing using natural gelatine, giving the paper incomparable resistance to scratching and exceptional rendering of colours.

ARCHES WATERCOLOUR PAPER

Arches watercolour paper is made of 100% cotton fibre giving it its great strength and stability. Arches is a mould made paper giving its characteristic texture and deckle edge. The paper is gelatine sized and air-dried.

ARCHIVAL PRINTS

Archival pigment printing denotes a printmaking process incorporating reﬁned particles of pigment that are resilient to the environmental elements that commonly degrade and erode dye molecules shortening the life of a print. This process has been implemented from the 19th century for image stability, winning out over methods such as traditional silver-halide or metal-based techniques for retaining image integrity.

ARTIST’S PROOF (A/P)

An artist’s proof is, at least in theory, an impression of a print taken in the printmaking process to see the current printing state of a plate while the plate (or stone, or woodblock…) is being worked on by the artist. A proof may show a clearly incomplete image, often called a working proof or trial impression, but in modern practice is usually used to describe an impression of the finished work that is identical to the numbered copies. There can also be printer’s proofs which are taken for the printer to see how the image is printing, or are final impressions the printer is allowed to keep; but normally the term “artist’s proof” would cover both cases. Artist’s proofs are not included in the count of a limited edition, and sometimes the number of artist’s proofs, which belong to the artist, can be surprisingly high at twenty or more. By convention, the artist is not supposed to sell these at once.

BLOTTING PAPER

A form of blotter paper commonly known as watercolour paper is produced for its absorbent qualities, allowing much better absorption of water and pigments than standard art or drawing papers. Although usually categorized as separate from blotting paper, differences in the constituents and thickness of blotting paper and watercolour paper are subtle, and making a distinction between the two is unnecessary as the production process is nearly identical.

BLU-RAY

Blu-ray Disc (BD) is a digital optical disc data storage format designed to supersede the DVD format, in that it is capable of storing high-definition video resolution (1080p). The name Blu-ray Disc refers to the blue laser used to read the disc, which allows information to be stored at a greater density than is possible with the longer-wavelength red laser used for DVDs. The main application of Blu-ray Discs is as a medium for video material such as feature films and physical distribution of video games for the PlayStation 3, PlayStation 4 and Xbox One. Besides the hardware specifications, Blu-ray Disc is associated with a set of multimedia formats.

C-PRINT

Chromogenic colour prints are full-colour photographic prints made using chromogenic materials and processes. These prints may be produced from an original, which is a colour negative, slide, or digital image. The chromogenic print process was nearly synonymous with the 20th century colour snapshot.

C-TYPE PHOTOGRAPH See C-PRINT

CAST VINYL FILM

The term “cast” refers to the manufacturing process of vinyls. This process also allows the film to be very thin (most cast films are 2 mil), which helps with the conformability of the product. Material manufacturers recommend the use of cast films on substrates such as fleets, vehicles, recreational vehicles or boats where the customer wants a “paint-like” finish that will last a long time, usually five to 12 years depending on how the film is processed. Because the vinyl is cast on the casting sheet in a relaxed state, this material offers very good dimensional stability.

CERAMIC

A ceramic is an inorganic, non-metallic solid prepared by the action of heat and subsequent cooling. Ceramic materials may have a crystalline or partly crystalline structure, or may be amorphous (e.g. a glass).

The earliest ceramics made by humans were pottery objects, including 27,000-year-old figurines, made from clay, either by itself or mixed with other materials, hardened in fire. Later ceramics were glazed and fired to create a coloured, smooth surface. Ceramics now include domestic, industrial and building products and a wide range of ceramic art.

CERAMIC GLAZE

Glaze is a layer or coating of a vitreous substance, which has been fused to a ceramic object through firing. Glaze can serve to colour, decorate, strengthen or waterproof an item.

CHARCOAL

Natural drawing charcoal is formed by the low-temperature carbonisation of soft, resin-free branches of wood in a vacuum.

CHINE-COLLE

Chine-collé is a special technique in printmaking. The purpose is to allow the printmaker to print on a much more delicate surface, such as Japanese paper, which pulls finer details off the plate. Another purpose is to provide colour behind the image that is different from the surrounding backing paper.

COLLAGE

Collage (From the French: coller, to glue) is a technique of an art production, primarily used in the visual arts, where the artwork is made from an assemblage of different forms, thus creating a new whole. A collage may sometimes include newspaper clippings, ribbons, bits of coloured or handmade papers, portions of other artwork or texts, photographs and other found objects, glued to a piece of paper or canvas.

COPPERPLATE PROCESS

Copper plating is the process in which a layer of copper is deposited on the item to be plated by using an electric current. Three basic types of processes are commercially available based upon the complex system utilised: alkaline (several modifications of cyanide and non-cyanide) complex bath, acid (sulphate and fluoborate) complex bath and mildly alkaline (pyro phosphate) complex bath. With a higher current, hydrogen bubbles will form on the item to be plated, leaving surface imperfections. Often various other chemicals are added to improve plating uniformity and brightness. Without some form of additive, it is almost impossible to obtain a smooth plated surface. These additives can be anything from dish soap to proprietary compounds.

DIASEC

Diasec is a registered trademark for a process used for face-mounting prints like photographs on acrylic sheets. The process was invented by Heinz Sovilla-Brulhart in 1969.

Because of the different light penetration and refraction of acrylic compared to normal glass, the colours are more brilliant and the image sharper than compared to standard glass in a picture frame.[citation needed] A Diasec mount is usually of a high gloss finish. Since the print is glued to the acrylic glass, the result is a completely flat mount of the image.

The print is also resistant to ultraviolet (UV) light because of the properties of acrylic glass.

DIBOND MIRROR (trademark)

DIBOND mirror is the first Aluminium composite panel of its kind and the result of significant R&D expenditure led by customer demand for a durable and distortion-free mirror sheet material. The durable and ultra-reflective mirror finish weighs just half as much as a glass mirror of the same thickness. This is an absolute advantage for transport, fixing and handling in terms of e.g. retail design, shop design and exhibitions stand building.

One of the most crucial issues about DIBOND mirror compared to mirrors out of glass is that DIBOND mirror would not burst – an essential criterion for local authorities, the hotel and leisure industries and other areas where public safety is paramount. DIBOND mirror can furthermore be directly digitally printed which reflects a new trend in sports centres, shopping malls and signage within the retail industry.

DIGITAL C-PRINT

Prints can also be exposed using digital exposure systems such as the Durst Lambda, Océ LightJet and ZBE Chromira, yielding a digital C-Type print (sometimes called a Lambda print or LightJet print). The LightJet and the Lambda both use RGB lasers to expose light-sensitive material to produce a latent image that is then developed using conventional silver based photographic chemicals. The Chromira uses LEDs instead of lasers which results in a faster imaging time but can result in banding and Moiré patterns in fine details if photographs submitted to the printer are at a size that differs from the actual crop and pixel resolution of the image file. All of the aforementioned printers utilise ICC colour profiles to achieve colour and density accuracy and also to correct paper sensitivity errors. The same technology can also be used to produce digital silver gelatin bromide black and white prints.

DIPTYCH

A work consisting of two painted or carved panels that are hinged together.

DOWEL

A dowel is a solid cylindrical rod, usually made of wood, plastic, or metal. In its original manufactured form, a dowel is called a dowel rod. Dowel rods are often cut into short lengths called dowel pins.

DURACLEAR

A clear-base color transparency material for use on illuminators with built-in diffusers (such as light boxes). They feature bright, saturated colors with deep intense blacks for extra impact. Also, they maintain superb detail from highlights to shadows and allow for very sharp text. Duraclear Display Material can be used for backlit displays such as advertising/point of sale, as well as for promotions, signage, lobbies and office space decor.

DURATRANS

A duratrans is an element used in some television news sets and theater designs. Duratrans are most often used to create the backgrounds that appear behind news presenters or anchors. If it is used in a theatre the backgrounds would appear behind the actors, actresses, and other talent respectively. Duratrans is short for Durable Transparency.

EPOXY RESINS

Epoxy resins, also known as polyepoxides are a class of reactive prepolymers and polymers, which contain epoxide groups. Epoxy has a wide range of industrial applications, including metal coatings, use in electronic and electrical components, high-tension electrical insulators, fibre-reinforced plastic materials, and structural adhesives. Epoxy resin is employed to bind gutta percha in some root canal procedures.

ETCHING

Etching is the process of using strong acid or mordant to cut into the unprotected parts of a metal surface to create a design in intaglio in the metal (the original process—in modern manufacturing other chemicals may be used on other types of material). As an intaglio method of printmaking, it is, along with engraving, the most important technique for old master prints, and remains in wide use today.

FIBRE-BASED PAPERS (FB)

Fibre-based (FB or Baryta) photographic papers consist of a paper base coated with baryta. Tints are sometimes added to the baryta to add subtle colour to the final print; however most modern papers use optical brighteners to extend the paper’s tonal range. Most fibre-based papers include a clear hardened gelatine layer above the emulsion, which protects it from physical damage, especially during processing. This is called a super coating. Papers without a super coating are suitable for use with the bromoil process. Fibre-based papers are generally chosen as a medium for high-quality prints for exhibition, display and archiving purposes. These papers require careful processing and handling, especially when wet. However, they are easier to tone, hand-colour and retouch than resin-coated equivalents.

GELATIN SILVER PRINTS

The gelatin silver process is the photographic process used with currently available black-and-white films and printing papers. This is one of the many ways of producing a photograph. A suspension of silver salts in gelatin is coated onto a support such as glass, flexible plastic or film, baryta paper, or resin-coated paper. These light-sensitive materials are stable under normal keeping conditions and are able to be exposed and processed even many years after their manufacture. This is in contrast to the collodion wet-plate process dominant from the 1850s–1880s, which had to be exposed and developed immediately after coating.

GICLEE PRINT

The term “Giclee print” connotes an elevation in printmaking technology. Images are generated from high resolution digital scans and printed with archival quality inks onto various substrates including canvas, fine art, and photo-base paper. The Giclee printing process provides better colour accuracy than other means of reproduction. Archival quality ensures that the prints are light-fast and non water soluble.

GOUACHE

Gouache, is a water based type of paint consisting of pigment, a binding agent (usually gum Arabic), and sometimes added inert material, designed to be used in an opaque and matt finish method. It also refers to paintings that use this opaque method. The name derives from the Italian guazzo. Gouache paint is similar to watercolour but modified to make it opaque. A binding agent, usually gum Arabic, is present, just as in watercolour. Gouache differs from watercolour in that the particles are larger, the ratio of pigment to water is much higher, and an additional, inert, white pigment such as chalk is also present. This makes gouache heavier and more opaque, with greater reflective qualities.

HAHNEMUHLE PAPERS (trademark)

The company was founded in 1584 and as such is the oldest German papermaker manufacturing papers for the traditional and digital artist as well as industrial paper. The traditional artist-paper range comprises: mould-made watercolour papers and academy-watercolour papers, copper-print and lithograph cardboards, mould-made papers for graphic-art printing, mould-made Ingres and Bugra papers, oil/acryl and pastel papers, sketch blocks and sketch books, papers from renewable bamboo fibres, passepartout and museum cardboards.

HIGH-DEFINITION (HD) VIDEO

High-definition video is video of higher resolution and quality than standard-definition. While there is no standardized meaning for high-definition, generally any video image with more than 480 horizontal lines (North America) or 576 lines (Europe) is considered high-definition. 720 scan lines is generally the minimum even though the majority of systems greatly exceed that. Images of standard resolution captured at rates faster than normal (60 frames/second North America, 50 fps Europe), by a high-speed camera may be considered high-definition in some contexts. Television series’ shot on high-definition video are made to look as if they have been shot on film, a technique that is often known as filmizing.

ILFOCHROME

Ilfochrome (also commonly known as Cibachrome) is a dye destruction positive-to-positive photographic process used for the reproduction of film transparencies on photographic paper. The prints are made on a dimensionally stable polyester base as opposed to traditional paper base. Since it uses 13 layers of azo dyes sealed in a polyester base, the print will not fade, discolour, or deteriorate for an extended time. Accelerated aging tests conducted by Henry Wilhelm indicated the product resisted fading under display conditions longer than any other known photographic colour material. Characteristics of Ilfochrome prints are image clarity, colour purity, as well as being an archival process able to produce critical accuracy to the original transparency.

INKJET PRINT

Inkjet printing is a type of computer printing that creates a digital image by propelling droplets of ink onto paper, plastic, or other substrates.

INTAGLIO ETCHING

Intaglio is the family of printing and printmaking techniques in which the image is incised into a surface, and the incised line or sunken area holds the ink. It is the direct opposite of a relief print. Normally, copper or zinc plates are used as a surface or matrix, and the incisions are created by etching, engraving, dry point, aquatint or mezzotint. Collagraphs may also be printed as intaglio plates.

LACQUER

Lacquer is a clear or coloured wood finish that dries by solvent evaporation or a curing process that produces a hard, durable finish. This finish can be of any sheen level from ultra matte to high gloss, and it can be further polished as required. It is also used for “lacquer paint”, which typically is a paint that dries to a more than usually hard and smooth surface.

In terms of modern products, lac-based finishes are referred to as shellac, while lacquer refers to other polymers dissolved in volatile organic compounds (VOCs), such as nitrocellulose, and later acrylic compounds dissolved in lacquer thinner, a mixture of several solvents typically containing butyl acetate and xylene or toluene. While both lacquer and shellac are traditional finishes, lacquer is more durable than shellac.

In terms of the decorative arts, lacquerware refers to variety of techniques used to decorate wood, metal or other surfaces, some involving carving into deep coatings of many layers of lacquer.

LINOCUT

Linocut is a printmaking technique, a variant of woodcut in which a sheet of linoleum (sometimes mounted on a wooden block) is used for the relief surface. A design is cut into the linoleum surface with a sharp knife, V-shaped chisel or gouge, with the raised (uncarved) areas representing a reversal (mirror image) of the parts to show printed. The linoleum sheet is inked with a roller (called a brayer), and then impressed onto paper or fabric. The actual printing can be done by hand or with a press.

MASONITE

Masonite is a type of hardboard made of steam-cooked and pressure-molded wood fibres in a process patented by William H. Mason. This product is also known as Quartrboard, Isorel, hernit, karlit, torex or treetex. Artists have often used it as a support for painting, and in artistic media such as linocut printing.

MATTBOARD

In the picture framing industry, a matt (or mount in British English) is a thin, flat piece of paper-based material included within a picture frame, which serves as additional decoration and to perform several other, more practical functions, such as separating the art from the glass and protecting the artwork.

MEDIUM-DENSITY FIBREBOARD (MDF)

Medium-density fibreboard (MDF) is an engineered wood product made by breaking down hardwood or softwood residuals into wood fibres, often in a defibrator, combining it with wax and a resin binder, and forming panels by applying high temperature and pressure. MDF is generally denser than plywood. It is made up of separated fibres, but can be used as a building material similar in application to plywood. It is stronger and much more dense than particle board.

The name derives from the distinction in densities of fibreboard. Large-scale production of MDF began in the 1980s, in both North America and Europe.

MIXED MEDIA

Mixed media, in visual art, refers to an artwork in the making of which more than one medium has been employed. There is an important distinction between “mixed-media” artworks and “multimedia art”. Mixed media tends to refer to a work of visual art that combines various traditionally distinct visual art media. For example, a work on canvas that combines paint, ink, and collage could properly be called a “mixed media” work, but not a work of “multimedia art.” The term multimedia art implies a broader scope than mixed media, combining visual art with non-visual elements (such as recorded sound, for example) or with elements of the other arts (such as literature, drama, dance, motion graphics, music, or interactivity). When creating a painted or photographed work using mixed media it is important to choose the layers carefully and allow enough drying time between the layers to ensure the final work will have structural integrity. If many different media are used it is equally important to choose a sturdy foundation upon which the different layers are imposed.

MONOPRINT

Monoprinting is a form of printmaking that has images or lines that can only be made once, unlike most printmaking, where there are multiple originals. There are many techniques of monoprinting. Examples of standard printmaking techniques, which can be used to make monoprints include lithography, woodcut, and etching.

MONOTYPING

Monotyping is a type of printmaking made by drawing or painting on a smooth, non-absorbent surface. The surface, or matrix, was historically a copper etching plate, but in contemporary work it can vary from zinc or glass to acrylic glass. The image is then transferred onto a sheet of paper by pressing the two together, usually using a printing-press. Monotypes can also be created by inking an entire surface and then, using brushes or rags, removing ink to create a subtractive image, e.g. creating lights from a field of opaque colour. The inks used may be oil based or water based. With oil based inks, the paper may be dry, in which case the image has more contrast, or the paper may be damp, in which case the image has a 10 percent greater range of tones.

Monotyping produces a unique print, or monotype; most of the ink is removed during the initial pressing. Although subsequent reprintings are sometimes possible, they differ greatly from the first print and are generally considered inferior. These prints from the original plate are called “ghost prints.” A print made by pressing a new print onto another surface, effectively making the print into a plate, is called a “cognate”. Stencils, watercolor, solvents, brushes, and other tools are often used to embellish a monotype print. Monotypes can be spontaneously executed and with no previous sketch.

MULTIPLE COPPER PLATE See Printmaking

MULTIPLATE ETCHING See Printmaking

MULTIPLATE PLATE BLEED See Printmaking

MUSEUM BOARD

Museum board is a type of paperboard. Specifically, it is a white, acid free cardboard that bends fairly easily in one direction but is fairly stiff in the other, due to the grain of the paper fibers.

OCEAN ETCHING

Luke Shelley created this printmaking technique. The copper plates are submerged within the ocean, in particular areas of high water movement. The plate is left for several weeks and endures the erosive nature of the ocean. Once Luke retrieves the plate, organic marks (random scratches, gouges, and oxidisation) are captured on the plate’s printable surface. These marks, according to Luke, record and emulate the movement of particles caught in the surges and turbulent waters.

OIL PAINT AND PAINTING

Oil paint is made of pigments ground in oil, usually linseed oil and is used in oil painting. Oil painting is the process of painting with pigments that are bound with a medium of drying oil. Commonly used drying oils include linseed oil, poppy seed oil, walnut oil, and safflower oil. The oil may be boiled with a resin, such as pine resin or frankincense to create a varnish; often prized for its body and gloss. Different oils confer various properties to the oil paint, such as less yellowing or different drying times. Certain differences are also visible in the sheen of the paints depending on the oil. An artist might use several different oils in the same painting depending on specific pigments and effects desired. The paints themselves also develop a particular consistency depending on the medium.

PAPER CUT-OUT

Papercutting is the art of cutting paper designs. The art has evolved uniquely all over the world to adapt to different cultural styles.

Cut-outs (or découpé in French) are not collages. They are, instead, a kind of sculpture made out of paper, carved by scissors instead of a chisel. They even might be considered very low bas-relief, mounted on a field of colored paper.

PAPER GSM

It is the paper density (also known as basis weight and grammage) is a term used in the pulp and paper industry to denote a measure of mass of the product per unit of area for a type of paper or paperboard. The term “density” is not used in its traditional sense of mass per unit volume. “Paper density”, rather, is a measure of the area density. The higher the GSM is, the heavier the paper is.

PERSPEX (trademark)

A solid transparent plastic made of polymethyl methacrylate (the same material as Plexiglas or Lucite) often used as a substitute for glass.

PHOTOGRAPHIC PAPERS

Photographic paper is a paper coated with a light-sensitive chemical formula, used for making photographic prints. When photographic paper is exposed to light it captures a latent image that is then developed to form a visible image. The light-sensitive layer of the paper is called the emulsion.

The print image is traditionally produced by interposing a photographic negative between the light source and the paper, either by direct contact with a large negative (forming a contact print) or by projecting the shadow of the negative onto the paper (producing an enlargement). The initial light exposure is carefully controlled to produce a grey scale image on the paper with appropriate contrast and gradation. Photographic paper may also be exposed to light using digital printers such as the Light Jet, with a camera (to produce a photographic negative), by scanning a modulated light source over the paper, or by placing objects upon it (to produce a photogram).

PHOTOPOLYMER

A photopolymer is a polymer that changes its properties when exposed to light, often in the ultraviolet or visible region of the electromagnetic spectrum. These changes are often manifested structurally, for example hardening of the material occurs as a result of cross-linking when exposed to light. An example is shown below depicting a mixture of monomers, oligomers, and photoinitiators that conform into a hardened polymeric material through a process called curing. A wide variety of technologically useful applications rely on photopolymers, for example some enamels and varnishes depend on photopolymer formulation for proper hardening upon exposure to light. In some instances, an enamel can cure in a fraction of a second when exposed to light, as opposed to thermally cured enamels which can require half an hour or longer. Curable materials are widely used for medical, printing, and photoresist technologies.

PIGMENTS

Pigments are the essential ingredients for artist’s paints and can also be used to colour all manner of materials. Mixed with linseed oil, they make oil paint; mixed with gum Arabic they make watercolour paints. They can be added to glue, plaster, melted wax, paper, varnishes, used for egg tempera, etc.

POLYURETHANE

Polyurethane (PUR and PU) is a polymer composed of a chain of organic units joined by carbamate (urethane) links. While most polyurethanes are thermosetting polymers that do not melt when heated, thermoplastic polyurethanes are also available.

Polyurethane products often are simply called “urethanes”, but should not be confused with ethyl carbamate, which is also called urethane. Polyurethanes neither contain nor are produced from ethyl carbamate.

Printmaking is the process of making artworks by printing, normally on paper. Printmaking normally covers only the process of creating prints that have an element of originality, rather than just being a photographic reproduction of a painting. Except in the case of monotyping, the process is capable of producing multiples of a same piece, which is called a print. Each print produced is not considered a “copy” but rather is considered an “original”. This is because typically each print varies to an extent due to variables intrinsic to the printmaking process, and also because the imagery of a print is typically not simply a reproduction of another work but rather is often a unique image designed from the start to be expressed in a particular printmaking technique. A print may be known as an impression. Printmaking (other than monotyping) is not chosen only for its ability to produce multiple impressions, but rather for the unique qualities that each of the printmaking processes lends itself to.

Prints are created by transferring ink from a matrix or through a prepared screen to a sheet of paper or other material. Common types of matrices include: metal plates, usually copper or zinc, or polymer plates for engraving or etching; stone, aluminium, or polymer for lithography; blocks of wood for woodcuts and wood engravings; and linoleum for linocuts. Screens made of silk or synthetic fabrics are used for the screen-printing process. Other types of matrix substrates and related processes are discussed below.

Multiple impressions printed from the same matrix form an edition. Since the late 19th century, artists have generally signed individual impressions from an edition and often number the impressions to form a limited edition; the matrix is then destroyed so that no more prints can be produced. Prints may also be printed in book form, such as illustrated books or artist’s books.

Printmaking techniques are generally divided into the following basic categories:

Relief: where ink is applied to the original surface of the matrix. Relief techniques include woodcut or woodblock as the Asian forms are usually known, wood engraving, linocut and metal cut.

Intaglio: where ink is applied beneath the original surface of the matrix. Intaglio techniques include engraving, etching, mezzotint, aquatint.

Planographic: where the matrix retains its original surface, but is specially prepared and/or inked to allow for the transfer of the image. Planographic techniques include lithography, monotyping, and digital techniques.

Stencil: where ink or paint is pressed through a prepared screen, including screen-printing and pochoir.

Other types of printmaking techniques outside these groups include: collagraphy, viscosity printing, and foil imaging. Collagraphy is a printmaking technique in which textured material is adhered to the printing matrix. This texture is transferred to the paper during the printing process. Contemporary printmaking may include digital printing, photographic mediums, or a combination of digital, photographic, and traditional processes.

Many of these techniques can also be combined, especially within the same family. For example Rembrandt’s prints are usually referred to as “etchings” for convenience, but very often include work in engraving and dry point as well, and sometimes have no etching at all.

RESIN

Resin in the most specific use of the term is a hydrocarbon secretion of many plants, particularly coniferous trees. More broadly, the term is also used for many thick liquids that harden into transparent solids.

Resins are valued for their chemical properties and associated uses, such as the production of varnishes, adhesives and food glazing agents. They are also prized as an important source of raw materials for organic synthesis, and provide constituents of incense and perfume.

SCREENPRINT

Screen printing is a stencil method of print making in which a design is imposed on a screen of polyester or other fine mesh, with blank areas coated with an impermeable substance. Ink is forced into the mesh openings by the fill blade or squeegee and onto the printing surface during the squeegee stroke. It is also known as silkscreen, serigraphy, and serigraph printing. One colour is printed at a time, so several screens can be used to produce a multicoloured image or design.

SCULPTURE

The art or practice of shaping figures or designs in the round or in relief, as by chiselling marble, modelling clay, or casting in metal. Sculpture is the branch of the visual arts that operates in three dimensions and one of the plastic arts. Durable sculptural processes originally used carving (the removal of material) and modelling (the addition of material, as clay), in stone, metal, ceramics, wood and other materials but, since modernism, shifts in sculptural process led to an almost complete freedom of materials and process. A wide variety of materials may be worked by removal such as carving, assembled by welding or modelling, or moulded, or cast.

SILICON

Any of a class of synthetic materials which are polymers with a chemical structure based on chains of alternate silicon and oxygen atoms, with organic groups attached to the silicon atoms. Such compounds are typically resistant to chemical attack and insensitive to temperature changes and are used to make rubber and plastics and in polishes and lubricants.

SILVER SCREEN

A silver screen, also known as a silver lenticular screen, is a type of projection screen that was popular in the early years of the motion picture industry and passed into popular usage as a metonym for the cinema industry. The term silver screen comes from the actual silver (or similarly reflective aluminium) content embedded in the material that made up the screen’s highly reflective surface.

Actual metallic screens are coming back into use in projecting 3-D films.

STEREOCOPY

Stereoscopy (also called stereoscopics or 3D imaging) is a technique for creating or enhancing the illusion of depth in an image by means of stereopsis for binocular vision. The word stereoscopy derives from Greek στερεός (stereos), meaning “firm, solid”, and σκοπέω (skopeō), meaning “to look, to see”. Any stereoscopic image is called stereogram. Originally, stereogram referred to a pair of stereo images, which could be viewed using a stereoscope.

Most stereoscopic methods present two offset images separately to the left and right eye of the viewer. These two-dimensional images are then combined in the brain to give the perception of 3D depth. This technique is distinguished from 3D displays that display an image in three full dimensions, allowing the observer to increase information about the 3-dimensional objects being displayed by head and eye movements.

STEREOGRAPHIC PROJECTIONS

In geometry, the stereographic projection is a particular mapping (function) that projects a sphere onto a plane. The projection is defined on the entire sphere, except at one point: the projection point. Where it is defined, the mapping is smooth and bijective. It is conformal, meaning that it preserves angles. It is neither isometric nor area preserving: that is, it preserves neither distances nor the areas of figures.

Intuitively, then, the stereographic projection is a way of picturing the sphere as the plane, with some inevitable compromises. Because the sphere and the plane appear in many areas of mathematics and its applications, so does the stereographic projection; it finds use in diverse fields including complex analysis, cartography, geology, and photography. In practice, the projection is carried out by computer or by hand using a special kind of graph paper called a stereographic net, shortened to stereonet or Wulff net.

STRETCHED CANVAS

A term in painting referring to canvas stretched and secured to a wooden frame (also known as a stretcher bar) to be used for original paintings and print reproductions. Canvases vary in quality and surface quality from cotton to Belgian linen and wood stretchers vary from pine to cedar for instance.

TRANSFER PAINTING

The practice of conserving an unstable painting on panel by transferring it from its original decayed, worm-eaten, cracked or distorted wood support to canvas or a new panel has been practised since the eighteenth century. It has now been largely superseded by improved methods of wood conservation.

The practice evolved in Naples and Cremona in 1711-25, and reached France by the middle of the eighteenth century. It was especially widely practiced in the second half of the 19th century. Similar techniques are used to transfer frescos.

TRIPTYCH

A triptych is a work of art (usually a panel painting) that is divided into three sections, or three carved panels which are hinged together and can be folded shut or displayed open. It is therefore a type of polyptych, the term for all multi-panel works. The middle panel is typically the largest and it is flanked by two smaller related works, although there are triptychs of equal-sized panels.

URETHANE See POLYURETHANE

VARNISH

Varnish is a transparent, hard, protective finish or film primarily used in wood finishing but also for other materials. Varnish is traditionally a combination of a drying oil, a resin, and a thinner or solvent. Varnish finishes are usually glossy but may be designed to produce satin or semi-gloss sheens by the addition of “flatting” agents. Varnish has little or no colour, is transparent, and has no added pigment, as opposed to paints or wood stains, which contain pigment and generally range from opaque to translucent. Varnishes are also applied over wood stains as a final step to achieve a film for gloss and protection. Some products are marketed as a combined stain and varnish.

VITRINE

A display case (also called a showcase or display cabinet, or a vitrine) is a cabinet with one or often more transparent glass (or plastic, normally acrylic for strength) sides and/or top, used to display objects for viewing, for example in an exhibition, museum, house, retail store, or restaurant. Often labels or prices are included with the displayed objects, providing information. In a museum, the displayed cultural artefacts are normally part of the museum’s collection. In retail, the objects are normally being offered for sale. A trophy case is used to display sports trophies or other awards.

A display case may be freestanding on the floor, or built-in (usually a custom installation). Built-in displays may be mounted on the wall, may act as room partitions, or may be hanging from the ceiling. On occasion, display cases are built into the floor, where the remains of drains and privies are shown in their original context, along with other archaeological artefacts

WATERCOLOUR PAINT AND PAINTING

Watercolour also Aquarelle from French, is a painting method. A watercolour is the medium or the resulting artwork in which the watercolour paints are made of pigments suspended in a water-soluble vehicle and Gum Arabic. The traditional and most common support for watercolour paintings is paper; other supports include papyrus, bark papers, plastics, vellum or leather, fabric, wood, and canvas. Watercolours are usually transparent, and appear luminous because the pigments are laid down in a relatively pure form with few fillers obscuring the pigment colours. Watercolour can also be made opaque by adding Chinese white. In East Asia, watercolour painting with inks is referred to as brush painting or scroll painting. In Chinese, Korean, and Japanese painting it has been the dominant medium, often in monochrome black or browns. India, Ethiopia and other countries also have long traditions. Finger painting with watercolour paints originated in China.